webrtc/RTCPeerConnection-addIceCandidate.html - external/w3c/web-platform-tests - Git at Google

 <!doctype html>
 <title>Test RTCPeerConnection.prototype.addIceCandidate</title>
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script>
  'use strict';

  // Test is based on the following editor draft:
  // https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.htm

  /*
  4.3.2. Interface Definition
  interface RTCPeerConnection : EventTarget {
  ...
  Promise<void> addIceCandidate((RTCIceCandidateInit or RTCIceCandidate) candidate);
  };

  interface RTCIceCandidate {
  readonly attribute DOMString candidate;
  readonly attribute DOMString? sdpMid;
  readonly attribute unsigned short? sdpMLineIndex;
  readonly attribute DOMString? ufrag;
  ...
  };

  dictionary RTCIceCandidateInit {
  DOMString candidate = "";
  DOMString? sdpMid = null;
  unsigned short? sdpMLineIndex = null;
  DOMString ufrag;
  };
  */

  // SDP copied from JSEP Example 7.1
  // It contains two media streams with different ufrags
  // to test if candidate is added to the correct stream
  const sdp = `v=0
 o=- 4962303333179871722 1 IN IP4 0.0.0.0
 s=-
 t=0 0
 a=ice-options:trickle
 a=group:BUNDLE a1 v1
 a=group:LS a1 v1
 m=audio 10100 UDP/TLS/RTP/SAVPF 96 0 8 97 98
 c=IN IP4 203.0.113.100
 a=mid:a1
 a=sendrecv
 a=rtpmap:96 opus/48000/2
 a=rtpmap:0 PCMU/8000
 a=rtpmap:8 PCMA/8000
 a=rtpmap:97 telephone-event/8000
 a=rtpmap:98 telephone-event/48000
 a=maxptime:120
 a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
 a=extmap:2 urn:ietf:params:rtp-hdrext:ssrc-audio-level
 a=msid:47017fee-b6c1-4162-929c-a25110252400 f83006c5-a0ff-4e0a-9ed9-d3e6747be7d9
 a=ice-ufrag:ETEn
 a=ice-pwd:OtSK0WpNtpUjkY4+86js7ZQl
 a=fingerprint:sha-256 19:E2:1C:3B:4B:9F:81:E6:B8:5C:F4:A5:A8:D8:73:04:BB:05:2F:70:9F:04:A9:0E:05:E9:26:33:E8:70:88:A2
 a=setup:actpass
 a=dtls-id:1
 a=rtcp:10101 IN IP4 203.0.113.100
 a=rtcp-mux
 a=rtcp-rsize
 m=video 10102 UDP/TLS/RTP/SAVPF 100 101
 c=IN IP4 203.0.113.100
 a=mid:v1
 a=sendrecv
 a=rtpmap:100 VP8/90000
 a=rtpmap:101 rtx/90000
 a=fmtp:101 apt=100
 a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
 a=rtcp-fb:100 ccm fir
 a=rtcp-fb:100 nack
 a=rtcp-fb:100 nack pli
 a=msid:47017fee-b6c1-4162-929c-a25110252400 f30bdb4a-5db8-49b5-bcdc-e0c9a23172e0
 a=ice-ufrag:BGKk
 a=ice-pwd:mqyWsAjvtKwTGnvhPztQ9mIf
 a=fingerprint:sha-256 19:E2:1C:3B:4B:9F:81:E6:B8:5C:F4:A5:A8:D8:73:04:BB:05:2F:70:9F:04:A9:0E:05:E9:26:33:E8:70:88:A2
 a=setup:actpass
 a=dtls-id:1
 a=rtcp:10103 IN IP4 203.0.113.100
 a=rtcp-mux
 a=rtcp-rsize
 `;

  const sessionDesc = { type: 'offer', sdp };

  // valid candidate attributes
  const sdpMid = 'a1';
  const sdpMLineIndex = 0;
  const ufrag = 'ETEn';

  const sdpMid2 = 'v1';
  const sdpMLineIndex2 = 1;
  const ufrag2 = 'BGKk';

  const mediaLine1 = 'm=audio';
  const mediaLine2 = 'm=video';

  const candidateStr1 = 'candidate:1 1 udp 2113929471 203.0.113.100 10100 typ host';
  const candidateStr2 = 'candidate:1 2 udp 2113929470 203.0.113.100 10101 typ host';
  const invalidCandidateStr = '(Invalid) candidate \r\n string';

  const candidateLine1 = `a=${candidateStr1}`;
  const candidateLine2 = `a=${candidateStr2}`;
  const endOfCandidateLine = 'a=end-of-candidates';

  // Copied from MDN
  function escapeRegExp(string) {
  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
  }

  // Check that a candidate line is found after the first media line
  // but before the second, i.e. it belongs to the first media stream
  function assert_candidate_line_between(sdp, beforeMediaLine, candidateLine, afterMediaLine) {
  const line1 = escapeRegExp(beforeMediaLine);
  const line2 = escapeRegExp(candidateLine);
  const line3 = escapeRegExp(afterMediaLine);

  const regex = new RegExp(`${line1}[^]+${line2}[^]+${line3}`);

  assert_true(regex.test(sdp),
  `Expect candidate line to be found between media lines ${beforeMediaLine} and ${afterMediaLine}`);
  }

  // Check that a candidate line is found after the second media line
  // i.e. it belongs to the second media stream
  function assert_candidate_line_after(sdp, beforeMediaLine, candidateLine) {
  const line1 = escapeRegExp(beforeMediaLine);
  const line2 = escapeRegExp(candidateLine);

  const regex = new RegExp(`${line1}[^]+${line2}`);

  assert_true(regex.test(sdp),
  `Expect candidate line to be found after media line ${beforeMediaLine}`);
  }

  // Reject because WebIDL for addIceCandidate does not allow null argument
  // null can be accidentally passed from onicecandidate event handler
  // when null is used to indicate end of candidate
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate(null)));
  }, 'Add null candidate should reject with TypeError');

  /*
  4.3.2. addIceCandidate
  4. Return the result of enqueuing the following steps:
  1. If remoteDescription is null return a promise rejected with a
  newly created InvalidStateError.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return promise_rejects(t, 'InvalidStateError',
  pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  }));
  }, 'Add ICE candidate before setting remote description should reject with InvalidStateError');

  /*
  Success cases
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  }));
  }, 'Add ICE candidate after setting remote description should succeed');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate(new RTCIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  })));
  }, 'Add ICE candidate with RTCIceCandidate should succeed');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({ sdpMid }));
  }, 'Add candidate with only valid sdpMid should succeed');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({ sdpMLineIndex }));
  }, 'Add candidate with only valid sdpMLineIndex should succeed');

  /*
  4.3.2. addIceCandidate
  4.6.2. If candidate is applied successfully, the user agent MUST queue
  a task that runs the following steps:
  2. Let remoteDescription be connection's pendingRemoteDescription
  if not null, otherwise connection's currentRemoteDescription.
  3. Add candidate to remoteDescription.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  }))
  .then(() => {
  assert_candidate_line_between(pc.remoteDescription.sdp,
  mediaLine1, candidateLine1, mediaLine2);
  });
  }, 'addIceCandidate with first sdpMid and sdpMLineIndex add candidate to first media stream');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr2,
  sdpMid: sdpMid2,
  sdpMLineIndex: sdpMLineIndex2,
  ufrag: ufrag2
  }))
  .then(() => {
  assert_candidate_line_after(pc.remoteDescription.sdp,
  mediaLine2, candidateLine2);
  });
  }, 'addIceCandidate with second sdpMid and sdpMLineIndex should add candidate to second media stream');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex,
  ufrag: null
  }))
  .then(() => {
  assert_candidate_line_between(pc.remoteDescription.sdp,
  mediaLine1, candidateLine1, mediaLine2);
  });
  }, 'Add candidate for first media stream with null ufrag should add candidate to first media stream');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  }))
  .then(() => pc.addIceCandidate({
  candidate: candidateStr2,
  sdpMid: sdpMid2,
  sdpMLineIndex: sdpMLineIndex2,
  ufrag: ufrag2
  }))
  .then(() => {
  assert_candidate_line_between(pc.remoteDescription.sdp,
  mediaLine1, candidateLine1, mediaLine2);

  assert_candidate_line_after(pc.remoteDescription.sdp,
  mediaLine2, candidateLine2);
  });
  }, 'Adding multiple candidates should add candidates to their corresponding media stream');

  /*
  4.3.2. addIceCandidate
  4.6. If candidate.candidate is an empty string, process candidate as an
  end-of-candidates indication for the corresponding media description
  and ICE candidate generation.
  2. If candidate is applied successfully, the user agent MUST queue
  a task that runs the following steps:
  2. Let remoteDescription be connection's pendingRemoteDescription
  if not null, otherwise connection's currentRemoteDescription.
  3. Add candidate to remoteDescription.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex, ufrag
  }))
  .then(() => pc.addIceCandidate({
  candidate: '',
  sdpMid, sdpMLineIndex,
  ufrag
  }))
  .then(() => {
  assert_candidate_line_between(pc.remoteDescription.sdp,
  mediaLine1, candidateLine1, mediaLine2);

  assert_candidate_line_between(pc.remoteDescription.sdp,
  mediaLine1, endOfCandidateLine, mediaLine2);
  });
  }, 'Add with empty candidate string (end of candidate) should succeed');

  /*
  4.3.2. addIceCandidate
  3. If both sdpMid and sdpMLineIndex are null, return a promise rejected
  with a newly created TypeError.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid: null,
  sdpMLineIndex: null
  })));
  }, 'Add candidate with both sdpMid and sdpMLineIndex manually set to null should reject with TypeError');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate({
  candidate: candidateStr1
  })));
  }, 'Add candidate with only valid candidate string should reject with TypeError');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate({
  candidate: invalidCandidateStr,
  sdpMid: null,
  sdpMLineIndex: null
  })));
  }, 'Add candidate with invalid candidate string and both sdpMid and sdpMLineIndex null should reject with TypeError');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate({})));
  }, 'Add candidate with empty dict should reject with TypeError');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, new TypeError(),
  pc.addIceCandidate({
  candidate: '',
  sdpMid: null,
  sdpMLineIndex: null,
  ufrag: undefined
  })));
  }, 'Add candidate with manually filled default values should reject with TypeError');

  /*
  4.3.2. addIceCandidate
  4.3. If candidate.sdpMid is not null, run the following steps:
  1. If candidate.sdpMid is not equal to the mid of any media
  description in remoteDescription , reject p with a newly
  created OperationError and abort these steps.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, 'OperationError',
  pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid: 'invalid', sdpMLineIndex, ufrag
  })));
  }, 'Add candidate with invalid sdpMid should reject with OperationError');

  /*
  4.3.2. addIceCandidate
  4.4. Else, if candidate.sdpMLineIndex is not null, run the following
  steps:
  1. If candidate.sdpMLineIndex is equal to or larger than the
  number of media descriptions in remoteDescription , reject p
  with a newly created OperationError and abort these steps.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, 'OperationError',
  pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMLineIndex: 2,
  ufrag
  })));
  }, 'Add candidate with invalid sdpMLineIndex should reject with OperationError');

  // There is an "Else" for the statement:
  // "Else, if candidate.sdpMLineIndex is not null, ..."
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid,
  sdpMLineIndex: 2,
  ufrag
  }));
  }, 'Invalid sdpMLineIndex should be ignored if valid sdpMid is provided');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() => pc.addIceCandidate({
  candidate: candidateStr2,
  sdpMid: sdpMid2,
  sdpMLineIndex: sdpMLineIndex2,
  ufrag: null
  }))
  .then(() => {
  assert_candidate_line_after(pc.remoteDescription.sdp,
  mediaLine2, candidateLine2);
  });
  }, 'Add candidate for media stream 2 with null ufrag should succeed');

  /*
  4.3.2. addIceCandidate
  4.5. If candidate.ufrag is neither undefined nor null, and is not equal
  to any ufrag present in the corresponding media description of an
  applied remote description, reject p with a newly created
  OperationError and abort these steps.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, 'OperationError',
  pc.addIceCandidate({
  candidate: candidateStr1,
  sdpMid, sdpMLineIndex,
  ufrag: 'invalid'
  })));
  }, 'Add candidate with invalid ufrag should reject with OperationError');

  /*
  4.3.2. addIceCandidate
  4.6.1. If candidate could not be successfully added the user agent MUST
  queue a task that runs the following steps:
  2. Reject p with a DOMException object whose name attribute has
  the value OperationError and abort these steps.
  */
  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, 'OperationError',
  pc.addIceCandidate({
  candidate: invalidCandidateStr,
  sdpMid, sdpMLineIndex, ufrag
  })));
  }, 'Add candidate with invalid candidate string should reject with OperationError');

  promise_test(t => {
  const pc = new RTCPeerConnection();

  return pc.setRemoteDescription(sessionDesc)
  .then(() =>
  promise_rejects(t, 'OperationError',
  pc.addIceCandidate({
  candidate: candidateStr2,
  sdpMid: sdpMid2,
  sdpMLineIndex: sdpMLineIndex2,
  ufrag: ufrag
  })));
  }, 'Add candidate with sdpMid belonging to different ufrag should reject with OperationError');

  /*
  TODO
  4.3.2. addIceCandidate
  4.6. In parallel, add the ICE candidate candidate as described in [JSEP]
  (section 4.1.17.). Use candidate.ufrag to identify the ICE generation;

  If the ufrag is null, process the candidate for the most recent ICE
  generation.

  - Call with candidate string containing partial malformed syntax, i.e. malformed IP.
  Some browsers may ignore the syntax error and add it to the SDP regardless.

  Non-Testable
  4.3.2. addIceCandidate
  4.6. (The steps are non-testable because the abort step in enqueue operation
  steps in before they can reach here):
  1. If candidate could not be successfully added the user agent MUST
  queue a task that runs the following steps:
  1. If connection's [[isClosed]] slot is true, then abort
  these steps.

  2. If candidate is applied successfully, the user agent MUST queue
  a task that runs the following steps:
  1. If connection's [[isClosed]] slot is true, then abort these steps.

  Issues
  w3c/webrtc-pc#1213
  addIceCandidate end of candidates woes

  w3c/webrtc-pc#1216
  Clarify addIceCandidate behavior when adding candidate after end of candidate

  w3c/webrtc-pc#1227
  addIceCandidate may add ice candidate to the wrong remote description

  w3c/webrtc-pc#1345
  Make promise rejection/enqueing consistent

  Coverage Report
  Total: 23
  Tested: 19
  Not Tested: 2
  Non-Testable: 2
  */
 </script>
	<!doctype html>
	<title>Test RTCPeerConnection.prototype.addIceCandidate</title>
	<script src="/resources/testharness.js"></script>
	<script src="/resources/testharnessreport.js"></script>
	<script>
	'use strict';

	// Test is based on the following editor draft:
	// https://w3c.github.io/webrtc-pc/archives/20170605/webrtc.htm

	/*
	4.3.2. Interface Definition
	interface RTCPeerConnection : EventTarget {
	...
	Promise<void> addIceCandidate((RTCIceCandidateInit or RTCIceCandidate) candidate);
	};

	interface RTCIceCandidate {
	readonly attribute DOMString candidate;
	readonly attribute DOMString? sdpMid;
	readonly attribute unsigned short? sdpMLineIndex;
	readonly attribute DOMString? ufrag;
	...
	};

	dictionary RTCIceCandidateInit {
	DOMString candidate = "";
	DOMString? sdpMid = null;
	unsigned short? sdpMLineIndex = null;
	DOMString ufrag;
	};
	*/

	// SDP copied from JSEP Example 7.1
	// It contains two media streams with different ufrags
	// to test if candidate is added to the correct stream
	const sdp = `v=0
	o=- 4962303333179871722 1 IN IP4 0.0.0.0
	s=-
	t=0 0
	a=ice-options:trickle
	a=group:BUNDLE a1 v1
	a=group:LS a1 v1
	m=audio 10100 UDP/TLS/RTP/SAVPF 96 0 8 97 98
	c=IN IP4 203.0.113.100
	a=mid:a1
	a=sendrecv
	a=rtpmap:96 opus/48000/2
	a=rtpmap:0 PCMU/8000
	a=rtpmap:8 PCMA/8000
	a=rtpmap:97 telephone-event/8000
	a=rtpmap:98 telephone-event/48000
	a=maxptime:120
	a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
	a=extmap:2 urn:ietf:params:rtp-hdrext:ssrc-audio-level
	a=msid:47017fee-b6c1-4162-929c-a25110252400 f83006c5-a0ff-4e0a-9ed9-d3e6747be7d9
	a=ice-ufrag:ETEn
	a=ice-pwd:OtSK0WpNtpUjkY4+86js7ZQl
	a=fingerprint:sha-256 19:E2:1C:3B:4B:9F:81:E6:B8:5C:F4:A5:A8:D8:73:04:BB:05:2F:70:9F:04:A9:0E:05:E9:26:33:E8:70:88:A2
	a=setup:actpass
	a=dtls-id:1
	a=rtcp:10101 IN IP4 203.0.113.100
	a=rtcp-mux
	a=rtcp-rsize
	m=video 10102 UDP/TLS/RTP/SAVPF 100 101
	c=IN IP4 203.0.113.100
	a=mid:v1
	a=sendrecv
	a=rtpmap:100 VP8/90000
	a=rtpmap:101 rtx/90000
	a=fmtp:101 apt=100
	a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
	a=rtcp-fb:100 ccm fir
	a=rtcp-fb:100 nack
	a=rtcp-fb:100 nack pli
	a=msid:47017fee-b6c1-4162-929c-a25110252400 f30bdb4a-5db8-49b5-bcdc-e0c9a23172e0
	a=ice-ufrag:BGKk
	a=ice-pwd:mqyWsAjvtKwTGnvhPztQ9mIf
	a=fingerprint:sha-256 19:E2:1C:3B:4B:9F:81:E6:B8:5C:F4:A5:A8:D8:73:04:BB:05:2F:70:9F:04:A9:0E:05:E9:26:33:E8:70:88:A2
	a=setup:actpass
	a=dtls-id:1
	a=rtcp:10103 IN IP4 203.0.113.100
	a=rtcp-mux
	a=rtcp-rsize
	`;

	const sessionDesc = { type: 'offer', sdp };

	// valid candidate attributes
	const sdpMid = 'a1';
	const sdpMLineIndex = 0;
	const ufrag = 'ETEn';

	const sdpMid2 = 'v1';
	const sdpMLineIndex2 = 1;
	const ufrag2 = 'BGKk';

	const mediaLine1 = 'm=audio';
	const mediaLine2 = 'm=video';

	const candidateStr1 = 'candidate:1 1 udp 2113929471 203.0.113.100 10100 typ host';
	const candidateStr2 = 'candidate:1 2 udp 2113929470 203.0.113.100 10101 typ host';
	const invalidCandidateStr = '(Invalid) candidate \r\n string';

	const candidateLine1 = `a=${candidateStr1}`;
	const candidateLine2 = `a=${candidateStr2}`;
	const endOfCandidateLine = 'a=end-of-candidates';

	// Copied from MDN
	function escapeRegExp(string) {
	return string.replace(/[.*+?^${}()\|[\]\\]/g, '\\$&');
	}

	// Check that a candidate line is found after the first media line
	// but before the second, i.e. it belongs to the first media stream
	function assert_candidate_line_between(sdp, beforeMediaLine, candidateLine, afterMediaLine) {
	const line1 = escapeRegExp(beforeMediaLine);
	const line2 = escapeRegExp(candidateLine);
	const line3 = escapeRegExp(afterMediaLine);

	const regex = new RegExp(`${line1}[^]+${line2}[^]+${line3}`);

	assert_true(regex.test(sdp),
	`Expect candidate line to be found between media lines ${beforeMediaLine} and ${afterMediaLine}`);
	}

	// Check that a candidate line is found after the second media line
	// i.e. it belongs to the second media stream
	function assert_candidate_line_after(sdp, beforeMediaLine, candidateLine) {
	const line1 = escapeRegExp(beforeMediaLine);
	const line2 = escapeRegExp(candidateLine);

	const regex = new RegExp(`${line1}[^]+${line2}`);

	assert_true(regex.test(sdp),
	`Expect candidate line to be found after media line ${beforeMediaLine}`);
	}

	// Reject because WebIDL for addIceCandidate does not allow null argument
	// null can be accidentally passed from onicecandidate event handler
	// when null is used to indicate end of candidate
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate(null)));
	}, 'Add null candidate should reject with TypeError');

	/*
	4.3.2. addIceCandidate
	4. Return the result of enqueuing the following steps:
	1. If remoteDescription is null return a promise rejected with a
	newly created InvalidStateError.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return promise_rejects(t, 'InvalidStateError',
	pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	}));
	}, 'Add ICE candidate before setting remote description should reject with InvalidStateError');

	/*
	Success cases
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	}));
	}, 'Add ICE candidate after setting remote description should succeed');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate(new RTCIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	})));
	}, 'Add ICE candidate with RTCIceCandidate should succeed');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({ sdpMid }));
	}, 'Add candidate with only valid sdpMid should succeed');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({ sdpMLineIndex }));
	}, 'Add candidate with only valid sdpMLineIndex should succeed');

	/*
	4.3.2. addIceCandidate
	4.6.2. If candidate is applied successfully, the user agent MUST queue
	a task that runs the following steps:
	2. Let remoteDescription be connection's pendingRemoteDescription
	if not null, otherwise connection's currentRemoteDescription.
	3. Add candidate to remoteDescription.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	}))
	.then(() => {
	assert_candidate_line_between(pc.remoteDescription.sdp,
	mediaLine1, candidateLine1, mediaLine2);
	});
	}, 'addIceCandidate with first sdpMid and sdpMLineIndex add candidate to first media stream');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr2,
	sdpMid: sdpMid2,
	sdpMLineIndex: sdpMLineIndex2,
	ufrag: ufrag2
	}))
	.then(() => {
	assert_candidate_line_after(pc.remoteDescription.sdp,
	mediaLine2, candidateLine2);
	});
	}, 'addIceCandidate with second sdpMid and sdpMLineIndex should add candidate to second media stream');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex,
	ufrag: null
	}))
	.then(() => {
	assert_candidate_line_between(pc.remoteDescription.sdp,
	mediaLine1, candidateLine1, mediaLine2);
	});
	}, 'Add candidate for first media stream with null ufrag should add candidate to first media stream');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	}))
	.then(() => pc.addIceCandidate({
	candidate: candidateStr2,
	sdpMid: sdpMid2,
	sdpMLineIndex: sdpMLineIndex2,
	ufrag: ufrag2
	}))
	.then(() => {
	assert_candidate_line_between(pc.remoteDescription.sdp,
	mediaLine1, candidateLine1, mediaLine2);

	assert_candidate_line_after(pc.remoteDescription.sdp,
	mediaLine2, candidateLine2);
	});
	}, 'Adding multiple candidates should add candidates to their corresponding media stream');

	/*
	4.3.2. addIceCandidate
	4.6. If candidate.candidate is an empty string, process candidate as an
	end-of-candidates indication for the corresponding media description
	and ICE candidate generation.
	2. If candidate is applied successfully, the user agent MUST queue
	a task that runs the following steps:
	2. Let remoteDescription be connection's pendingRemoteDescription
	if not null, otherwise connection's currentRemoteDescription.
	3. Add candidate to remoteDescription.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex, ufrag
	}))
	.then(() => pc.addIceCandidate({
	candidate: '',
	sdpMid, sdpMLineIndex,
	ufrag
	}))
	.then(() => {
	assert_candidate_line_between(pc.remoteDescription.sdp,
	mediaLine1, candidateLine1, mediaLine2);

	assert_candidate_line_between(pc.remoteDescription.sdp,
	mediaLine1, endOfCandidateLine, mediaLine2);
	});
	}, 'Add with empty candidate string (end of candidate) should succeed');

	/*
	4.3.2. addIceCandidate
	3. If both sdpMid and sdpMLineIndex are null, return a promise rejected
	with a newly created TypeError.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid: null,
	sdpMLineIndex: null
	})));
	}, 'Add candidate with both sdpMid and sdpMLineIndex manually set to null should reject with TypeError');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate({
	candidate: candidateStr1
	})));
	}, 'Add candidate with only valid candidate string should reject with TypeError');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate({
	candidate: invalidCandidateStr,
	sdpMid: null,
	sdpMLineIndex: null
	})));
	}, 'Add candidate with invalid candidate string and both sdpMid and sdpMLineIndex null should reject with TypeError');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate({})));
	}, 'Add candidate with empty dict should reject with TypeError');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, new TypeError(),
	pc.addIceCandidate({
	candidate: '',
	sdpMid: null,
	sdpMLineIndex: null,
	ufrag: undefined
	})));
	}, 'Add candidate with manually filled default values should reject with TypeError');

	/*
	4.3.2. addIceCandidate
	4.3. If candidate.sdpMid is not null, run the following steps:
	1. If candidate.sdpMid is not equal to the mid of any media
	description in remoteDescription , reject p with a newly
	created OperationError and abort these steps.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, 'OperationError',
	pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid: 'invalid', sdpMLineIndex, ufrag
	})));
	}, 'Add candidate with invalid sdpMid should reject with OperationError');

	/*
	4.3.2. addIceCandidate
	4.4. Else, if candidate.sdpMLineIndex is not null, run the following
	steps:
	1. If candidate.sdpMLineIndex is equal to or larger than the
	number of media descriptions in remoteDescription , reject p
	with a newly created OperationError and abort these steps.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, 'OperationError',
	pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMLineIndex: 2,
	ufrag
	})));
	}, 'Add candidate with invalid sdpMLineIndex should reject with OperationError');

	// There is an "Else" for the statement:
	// "Else, if candidate.sdpMLineIndex is not null, ..."
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid,
	sdpMLineIndex: 2,
	ufrag
	}));
	}, 'Invalid sdpMLineIndex should be ignored if valid sdpMid is provided');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() => pc.addIceCandidate({
	candidate: candidateStr2,
	sdpMid: sdpMid2,
	sdpMLineIndex: sdpMLineIndex2,
	ufrag: null
	}))
	.then(() => {
	assert_candidate_line_after(pc.remoteDescription.sdp,
	mediaLine2, candidateLine2);
	});
	}, 'Add candidate for media stream 2 with null ufrag should succeed');

	/*
	4.3.2. addIceCandidate
	4.5. If candidate.ufrag is neither undefined nor null, and is not equal
	to any ufrag present in the corresponding media description of an
	applied remote description, reject p with a newly created
	OperationError and abort these steps.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, 'OperationError',
	pc.addIceCandidate({
	candidate: candidateStr1,
	sdpMid, sdpMLineIndex,
	ufrag: 'invalid'
	})));
	}, 'Add candidate with invalid ufrag should reject with OperationError');

	/*
	4.3.2. addIceCandidate
	4.6.1. If candidate could not be successfully added the user agent MUST
	queue a task that runs the following steps:
	2. Reject p with a DOMException object whose name attribute has
	the value OperationError and abort these steps.
	*/
	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, 'OperationError',
	pc.addIceCandidate({
	candidate: invalidCandidateStr,
	sdpMid, sdpMLineIndex, ufrag
	})));
	}, 'Add candidate with invalid candidate string should reject with OperationError');

	promise_test(t => {
	const pc = new RTCPeerConnection();

	return pc.setRemoteDescription(sessionDesc)
	.then(() =>
	promise_rejects(t, 'OperationError',
	pc.addIceCandidate({
	candidate: candidateStr2,
	sdpMid: sdpMid2,
	sdpMLineIndex: sdpMLineIndex2,
	ufrag: ufrag
	})));
	}, 'Add candidate with sdpMid belonging to different ufrag should reject with OperationError');

	/*
	TODO
	4.3.2. addIceCandidate
	4.6. In parallel, add the ICE candidate candidate as described in [JSEP]
	(section 4.1.17.). Use candidate.ufrag to identify the ICE generation;

	If the ufrag is null, process the candidate for the most recent ICE
	generation.

	- Call with candidate string containing partial malformed syntax, i.e. malformed IP.
	Some browsers may ignore the syntax error and add it to the SDP regardless.

	Non-Testable
	4.3.2. addIceCandidate
	4.6. (The steps are non-testable because the abort step in enqueue operation
	steps in before they can reach here):
	1. If candidate could not be successfully added the user agent MUST
	queue a task that runs the following steps:
	1. If connection's [[isClosed]] slot is true, then abort
	these steps.

	2. If candidate is applied successfully, the user agent MUST queue
	a task that runs the following steps:
	1. If connection's [[isClosed]] slot is true, then abort these steps.

	Issues
	w3c/webrtc-pc#1213
	addIceCandidate end of candidates woes

	w3c/webrtc-pc#1216
	Clarify addIceCandidate behavior when adding candidate after end of candidate

	w3c/webrtc-pc#1227
	addIceCandidate may add ice candidate to the wrong remote description

	w3c/webrtc-pc#1345
	Make promise rejection/enqueing consistent

	Coverage Report
	Total: 23
	Tested: 19
	Not Tested: 2
	Non-Testable: 2
	*/
	</script>